After being left out of multiple family trips, I went on my mom's dream vacation to Scotland

My mom is constantly taking trips with my sister, her husband, and their kids. I'm always the one they ask to watch their house and animals while they're gone. I have always felt left out of family vacations and that my mom prefers my sister over me. I recently saved up enough money to take a trip of my own. My mom has always wanted to go to Scotland, it's like a life dream for her. I decided that I was going to take my own vacation to Scotland and for a companion, I chose my aunt who is my mom's least favorite sister and the only family member that supports me. My mom is constantly arguing with my aunt, probably because she's always been jealous of her lifestyle (aunt is very wealthy). Of course my mom begged me to take her instead but I absolutely refused her, stating my reasons (never being included in her trips and using me as a dog/house sitter). I made sure to send her updates of everywhere I went and sent all my pictures to her daily.